Landscape gardening is as much fashion as it is function, and personal style often comes into play. Take moss, for example. Most Canadians consider moss to be a weed in the lawn, but in a country like Japan it is grown and admired in the landscape. Moss grows in many colours, shapes and sizes, all of which you might observe as you bicycle along a roadway or walk in the woods or on the natural barrens. Allowing it to thrive in your garden could add a whole new dimension to your landscape.
Moss plants are an amazing group with a variety of interesting characteristics. They grow without a root system; they have rhizoids, which enable them to cling to a surface. They don’t get their nutrients from the soil - they don’t even respond to nutrients or pH of the soil. They get their nutrients from the air, sunlight and rain. Moss plants reproduce by spores, which are distributed primarily by air movement.
The Sphagnum species of moss that has accumulated over thousands of years has formed what are called peat bogs, which can cover hundreds of acres. Sphagnum moss, in association with other plants, is a critical part of the ecosystem in Newfoundland and Labrador. We have used the peat material from the bog in various ways: as a growing media, as an amendment to improve natural mineral soil and in dried form for fuel. In local home remedies, peat moss has been used in the past as an absorbent and a sterile dressing.
How to eliminate moss in your lawn
In a mowed grass lawn, moss is considered a weed by many homeowners. So-called “moss killer” chemicals do not work very well, though, because they just burn off the moss and damage the grass. Moss is a naturally occurring plant that will grow anywhere the grass is not growing properly. Lawn grass, on the other hand, is not a native plant, so it must be maintained with regular applications of lime and fertilizer in order to compete with moss.
To maintain a healthy grass lawn, you need to start with at least six inches of good topsoil. Soil on established lawns can be improved by top dressing with a finely screened soil mixture. Lime should be applied once every year at the rate of 10 lbs per 100 ft.². Fertilize with a complete fertilizer like 15-5-15 in the spring, in mid-summer and again in the fall at the rate of 3 lbs per 100 ft.² each time. If the grass is growing well, a lower rate of fertilizer would be okay; if not, you may have to increase the ratio of lime and fertilizer to get desired results. Mow the grass as high as possible, and mow often so that only the top third of the grass is removed each time. At least two inches of green grass should remain after mowing. If the grass is mowed too close to the ground, moss will get established.
As you can see from these recommendations, maintaining a healthy grass lawn is an expensive and time-consuming gardening activity. Perhaps rather than fight the moss, you could learn to live with it, and even enjoy it.
How to create a moss garden
The main problem people have with moss is that it is not nice to play or walk on. If you are not using the area, though, moss makes an excellent ground cover. It doesn’t have to be mowed or maintained with lime and fertilizer, it will grow in very shaded areas where growing grass is a problem, and it is winter hardy.
One of the first steps in planning a moss garden is identifying the various species of moss and knowing their characteristics. Depending on the type of moss, it can grow in sun or shade and in wet or dry areas. The various colours of the different species of moss make beautiful contrast in the landscape. Add in some rocks for definition and you can create an interesting display. (Moss will grow on rocks as well as on soil, so if you have a shaded area where it is difficult to grow grass, consider a moss and rock garden.)
Get design ideas by observing what occurs in nature. Take a trip to local barrens and photograph mossy areas. Maybe you can replicate a small pool as a garden water feature, or incorporate weather-beaten rocks or boulders that contain natural lichens. This sort of design can add a degree of serenity and beauty that is very low maintenance.
Once you have a plan in mind, you can forage for moss in the wild. A small area (a square foot or so) where moss was growing will quickly fill in again, so there’s no real damage to the environment. As moss has no real roots, it’s very easy to take it up for transplanting. It is best to divide a larger colony into smaller pieces for transplanting. One square-foot colony of moss can be divided into fragments to cover up to 20 ft.² in a new area.
Once you have your design and your plants, creating a moss garden is not difficult. But you do need to understand a little bit about the nature of moss plants. Moss needs moisture to grow and reproduce; when it is dry it simply shuts down and goes dormant. Therefore, the best time to transplant moss is in the spring, when there is more moisture in the soil. Organic matter, such as compost, in the soil helps retain moisture needed for moss to grow. An irrigation system would be beneficial during the dry weather in the summer.
Because it does not respond to lime or fertilizer, there is no need to go to a lot of trouble to prepare the soil underneath. If you’re aiming to keep a weed-free moss garden, an herbicide like Roundup can be used to kill competing weeds and grass without harming your moss. Of course, hand weeding is an option for small areas.
Overall, a moss garden can be very rewarding, giving you a natural landscape that doesn’t have to be mowed, thrives in shade, and can tolerate dry and wet conditions. For these reasons, a moss garden is worth considering, even on a small scale. Remember, beauty is in the eye of the beholder! - By Ross Traverse
Ross Traverse has been a horticultural consultant to gardeners and farmers for more than 40 years. His "Down to Earth" column appears in each issue of Downhome.